November 11 Flashcards
Incidence
The number of new cases of a disease in a given time
Prevalence
Total number of new and existing cases in a given time
Outbreak
Number of cases of diseases are reported in a short period of time
Mortality
Incidence of death in a population
Morbidity
Incidence of disease including both fatal and nonfatal cases
Subclinical Infection
No clinical symptoms/signs “carriers”
Reservoirs
Sites where infectious agents remain viable (could be geographical or a person) from which infection can occur
Example: Clostridium tetani soil is a reservior for it, it prodcuses endospores. Some viruses–birds can act as reserviors, monkeys
Carriers can act as reseriors, but it usually refers to a larger population.
Carriers
Asymptomatic, potential source of infection, may be in incubation period of the disease
How do you identify a carrier?
Cultures and immunoassays–looking for specific antibodies produced when exposed to antigens
Transmission
Can be direct or indirect
Direct Transmission: infected individual transmits disease directly–host to host (STIs, flu, ringworm, colds)
Indirect Transmission: facilitated by living or nonliving agents
Vector
Living agent that transmits disease
Example: mosquitos transmit malayria
Fomite
Nonliving, inanimate pathogen carrier
Herd Immunity
Resistance of a group to infection due to immunity of a high proportion of individuals of the group
An entire group is protected, immunized people protect non-immunized people because the pathogen is not passed
A breakdown in herd immunity is caused by a decrease in vaccinations (Thanks Jenny McCartney)
Nosocomial Infection
Healthcare associated infection
Why are these pathogens spread?
Low resistance
Rooms with more than one patient
Workers move from patient to patient
Procedures introduce cuts and punctures to the skin (providing a portal of entry for pathogens)
Surgery
Use of antibiotics- microbes constantly exposed to antibiotics
